As webmasters dabble into the land of exciting possibilities enabled by recent developments in browser technology, it's essential to remember that different users use different browsers, and webpages that work in one browser will not necessarily work in another. But developer time is limited - so, how important is it for a scholarly website to support version N of browser B? To help answer this qestion, here's the breakdown of Google Scholar searches by browser, fresh from the logs.

Fraction of Google Scholar searches by browser for periods ending August 2, 2011.

year

month

day

Internet Explorer

59%

47%

46%

Firefox

25%

23%

23%

Chrome & Safari

10%

19%

20%

Unknown

5%

10%

10%

Other

1%

1%

1%

And now for the fine print...

This table doesn't necessarily represent trends in browser adoption, because Google Scholar usage is qualitatively different throughout the year. In particular, summer numbers do not include frantic searches by thundering herds of students studying for their exams; but annual numbers do.

These numbers are certainly heavily influenced by English searches. However, over half of our usage is from outside the US, and non-English speakers tend to search in their own language. Yes, for papers too; yes, I checked; and yes, some of their searches are in English. All things considered, I think the world stats should work well for most websites.

As of last month, versions 7, 8 and 9 of Internet Explorer were used in 18%, 21% and 3% of all searches, respectively. Versions 5 and 6 carry some, uhh, surprises for developers, but luckily their usage has dropped from 3% + 15% = 18% in the annual stats to 0% + 5% = 5% in the monthly stats. So, that settles it - we will only test Google Scholar with IE7+ going forward.

Firefox-wise, 10% of total usage is from version 3, and the vast majority of the remaining 13% is from versions 4 and 5. All three versions are quite similar in their rendering of HTML, so it's often sufficient to cover just the latest version in testing.

I have combined the two Webkit-based browsers, Chrome and Safari, because their rendering of HTML is nearly identical. For minor changes, we often test the latest version of Chrome and skip Safari, because Chrome's usage is currently 15% vs. Safari's 5%. Both of these browsers tend to be reasonably up to date - the vast majority of their searches last month came from Chrome versions 12 and 13 and Safari version 5.

All mobile browsers combined currently make up a very small fraction of searches, though whether one can call millions of searches "very small" is certainly a matter of perspective. The same applies to Opera and to a number of other browsers and platforms. Occasional testing of infrequently used browsers is key to a reasonable balance between serving your users and taking forever to rollout.

Bottom line? We recommend that you test your scholarly website with at least three browsers - Internet Explorer 7+, Firefox 3+, and Chrome 12+. If it doesn't work with either one of these browsers, then it likely doesn't work for a lot of your users.